1. Field of the Invention
Embodiments of the invention relates generally to drivers for storage systems, and more specifically, to multipath drivers for storage systems that include an external boot device.
2. Description of Related Art
Storage technology is important for systems that run data intensive applications. Currently, there are various storage devices having different capacities and streaming rates to accommodate various applications. Examples of these storage devices include redundant array of independent disks (RAIDs), tape drives, disk drives, and tape libraries. These devices may be connected to a system using various techniques such as the direct-attached storage technique, or storage area networks (SANs) (switch environment technique).
Existing multipath drivers to interface with these storage devices have a number of drawbacks. First, they do not provide a common driver for managing different types of devices. In other words, they are not universal. A system typically has to install several different types of drivers, one for each type of storage device. This creates complexity in management and system administration, increases cost in software acquisition and maintenance, and reduces system reliability and re-configurability. Second, existing techniques do not provide failover (and failback) for and among different storage devices, reducing system fault-tolerance and increasing server downtime. Third, they do not provide load balancing among different storage devices, causing performance degradation when there is skew in storage utilization.